Deterring theft of optical media

ABSTRACT

An optical media disk is treated with a light-sensitive material that impedes the ability of a optical media player from reading data stored on the disk. This light-sensitive material is a material changes phase upon exposure to one or more wavelengths of light. During the initial phase, the light-sensitive material will render the disk unreadable. After activation, however, the disk becomes readable by conventional optical media players. In this fashion, theft of yet-to-be-activated optical media is deterred.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 60/664,164 filed on Mar. 21, 2005.

FIELD OF THE INVENTION

The invention relates in general optical media content, and inparticular, to preventing unauthorized access of the media content untilthe media is activated by exposure to a predetermined light source.

BACKGROUND OF THE INVENTION

Optical data storage media (“optical media”) are media in which data isstored in an optically readable manner. Data is encoded by opticalchanges in one or more layers of the media. Formats of optical mediuminclude read-only formats such as CD-DA (digital audio compact disc),CD-ROM (CD-read-only memory), DVD (digital versatile disc or digitalvideo disc) Blu-ray ROM media, write-once read-many times (WORM) formatssuch as CD-R (CD-recordable), and DVD-R (DVD-recordable), as well asrewritable formats such as found on magneto-optical (MO) discs, CD-RW(CD-rewriteable), DVD-RAM (DVD-Random Access Media), DVD-RW or DVD+RW(DVD-rewriteable), PD (Phase change Dual disk by Panasonic), Blu-ray REand other phase change optical discs.

Optical media are susceptible to theft all along the supply chain. Forexample, optical media disks are commonly placed on shelves in theretail-leasing establishment, thereby being susceptible of theft. Evenif the optical media disks are stored in cases containing, for example,an electronic article surveillance (“EAS”) tag or label, the opticalmedia can typically be removed from the storage case with difficulty. Infact, optical media are susceptible to being removed from shippingcartons or from individual cases before even reaching a final point ofsale.

Current approaches to combating the optical media theft problem has beento make the media cases difficult to open, embed EAS or RFID tags in themedia cases, increase video surveillance along the supply chain, orsimply reducing consumer's unsupervised access to the product. However,each of these approaches is met with several disadvantages, includingeasy of circumvention and cost.

In addition to the theft problem of optical media, it may some times bedesirable to prevent access of the optical media content that isotherwise lawfully being possessed. For example, one may want todistribute optical media but delay it access until the occurrence ofsome future event (e.g., payment).

Thus, there is still an unsatisfied need for a system and method forpreventing the unauthorized access of optical media content.

SUMMARY OF THE INVENTION

Systems and methods for preventing the unauthorized access of opticalmedia content. In one embodiment, a method includes encoding data on anoptical media, treating a substrate surface of the optical media with alight-sensitive material that is in a first phase, where thelight-sensitive material deters theft of the optical media by causingthe encoded data to be unreadable while in the first phase. The methodfurther includes activating, prior to a point of sale of the opticalmedia, the light-sensitive material using a light source having apredetermined wavelength, wherein activating the light-sensitivematerial causes it to change from the first phase to a second phase,after which the encoded data is readable.

Other embodiments are disclosed and claimed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B depict typical optical media disks from a side view andcross-section, respectively;

FIG. 2 is a cross-sectional view of an optical media disk consistentwith one embodiment of the invention; and

FIG. 3 is a flow diagram for a process of implementing one embodiment ofthe invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

One aspect of the invention is to treat optical media with alight-sensitive material which impedes the ability of a optical mediaplayer from reading data stored on the optical media. In one embodiment,this light-sensitive material may be any material capable of beingactivated so as to change in a physically measurable manner, uponexposure to one or more wavelengths of light. In another embodiment, thelight-sensitive material may be any embodiment of the light-changeablecompounds disclosed in U.S. Pat. No. 6,589,626, which issued on Jul. 8,2003, and which is hereby fully incorporated by reference (hereinafterthe “'626 Patent”).

Another aspect of the invention is to activate the treated optical mediausing a particular wavelength (or range of wavelengths) of light,thereby causing the aforementioned light-sensitive material to changeits phase such that conventional optical media players will be able tosubsequently read the media's encoded data. While in one embodiment, theentire optical media may be treated with the light-sensitive material,in another embodiment only particular sections may be treated. Accordingto one embodiment, once activated, the light-sensitive material willpermanently remain in its new state. In one embodiment, the light sourceis a mercury light source, however numerous other light sources may besimilarly used.

In one embodiment, optical media are treated with the aforementionedlight-sensitive material shortly after the traditional data encodingprocess is complete. The optical media is then placed in the supplychain for delivery to its ultimate point of sale. After a particularpoint in the supply chain, the optical media may be activated using apredetermined wavelength of light. It should be appreciated that thepredetermined wavelength of light, or range thereof, will depend on theparticular light-sensitive material used, as disclosed in the '626Patent. While in one embodiment, activation occur at the final point ofsale, it may similarly occur at some earlier point along the productsupply line. In this fashion, theft of the yet-to-be-activated opticalmedia is deterred since it will be unreadable. It may further bedesirable to label the optical media (or its casing) as being inactiveso as to increase the deterrent effect.

The physical specifications for optical media are standards known in theart. All media dimensions, including those pertaining to pit andphysical formations, which encode data, are defined in the CD standard.For example, specifications information on sampling frequency,quantization word length, data rate, error correction code, andmodulation scheme are all defined in the standard. Properties of theoptical system that reads data from the disc using a laser beam are alsodefined in the standard.

Referring to prior art FIGS. 1A and 1B, the physical characteristics ofa typical optical media surface are described. In FIG. 1A, optical disk100 is approximately 120 mm in diameter. The innermost portion of thedisk is a hole, with a diameter of approximately 15 mm, usable to mountthe optical disk to a rotating mount coupled to a spindle motor shaft.

Referring now to FIG. 1B, depicted is a magnified cross-section ofoptical disk's 100 surface. As shown, the disk substrate 110 istypically a plastic substrate which comprises most of the disk's overallthickness. Directly on the disk substrate, a thin metal layer 120 ofgenerally aluminum, silver or gold is deposited. Data is physicallycontained in the metalized pits impressed along the optical disk'ssurface, as shown in FIG. 1B. Above this metalized pit surface 120 anddisc substrate 110 is deposited a protective lacquer coating 130 whichis typically between 10 and 30 micrometers thick. An identifying label140 (5 micrometers) is often affixed to the top of the lacquer coating.

Continuing to refer to FIG. 1B, a beam of laser light is used to readthe data from the encoded media surface. A laser beam, which is focusedon the metalized data surface 120, is applied to the underside of thedisk such that it passes through the transparent disk substrate 110 andback out again. As the disk rotates, the laser beam moves across thedisc from the center to the edge. Binary code signals generated by thebeam's reflective pattern are then converted into digital data such as,for example, audio and video data. The media must present two states sothe change between them varies the reflected light, and thus data can berecognized. Data can be represented as a phase change, polarizationchange, or change in the intensity of the reflected light.

Referring now to FIG. 2, depicted is a cross-sectional view of anoptical media disk 200 consistent with one embodiment of the invention.In this embodiment the underside of the optical disk 200, which iscomprised of the disk substrate, has been coated with a light-sensitivematerial 210. It should be appreciated that numerous methods ofapplications may be used and be consistent with the invention. Forexample, any of the techniques disclosed in the '626 Patent may be used,such as by placing the light-sensitive material between two substrates,applying it as a polymeric film to the disk 200, etc.

In one embodiment, the light-sensitive material 210 prevents the opticalmedia disk 200 from being read by a conventional optical media player.That is, the laser beam reflection pattern is altered by the appliedlight-sensitive material 210. However, the nature of the light-sensitivematerial 210 is that some of its physical properties can be altered byexposure to particular wavelengths of light. That is, in one embodimentexposing the light-sensitive material 210 to a certain type of lightwill cause the phase of the light-sensitive material 210 to change,thereby allowing the optical disk 200 to be read again. In oneembodiment, the activating light source is a mercury-based light source.

Referring now to FIG. 3, depicted is one embodiment of a process forimplementing one or more aspects of the invention. This process assumesthat data has already been recorded to the subject disk. Process 300begins at block 310 with the light-sensitive material (e.g., material210) being applied to the disk substrate. As previously mentioned, itshould be appreciated that numerous methods of applications may be usedand be consistent with the invention. However, in one embodiment themost (or all) of the disk surface may be coated with the light-sensitivematerial.

At this point, the applied light-sensitive material has placed the diskin an error state (block 320), rendering it unreadable by a traditionaloptical media player. In one embodiment, this error state is a result ofthe optical media player's laser not being able to accurately penetratethe light-sensitive material covering the disk surface. The disk maythen be packaged for shipment out to the end user at block 330. In oneembodiment, theft of the disk at any point along the supply chain willbe deterred by the fact that the disk is unreadable until properactivation.

Continuing to refer to FIG. 3, process 300 continues to block 340 wherethe treated disk may be activated. In one embodiment, activation isaccomplished by exposing the disk surface (and hence the light-sensitivematerial itself) to a particular light wavelength or range ofwavelengths. In one embodiment, the disk may be activated (i.e., exposedto the activating light) while still in a case. In situations where theoptical media is being stored and/or displayed in a transparent ortranslucent plastic storage case, the activation process can occurthrough the case itself so long as the case is at least translucent tothe particular wavelength of light being used to activate the enclosedmedia.

As previously mentioned, the light-sensitive or light-changeablematerial of the invention may be any of the light-sensitive orlight-changeable materials disclosed in the '626 Patent. For example,the light-sensitive material may be organic material or inorganicmaterial; a cyanine compound; an organic light-changeable materialexcitable by a light source emitting light at a wavelength between about770 nm to about 830 nm or between about 630 nm to about 650 nm; or aninorganic material capable of undergoing a phase change from anamorphous state to a crystalline state by absorption of energy from oneor more wavelengths of light. In one embodiment, the inorganicphase-change light-changeable material may be GeSbTe, InSbTe, InSe,AsTeGe, TeO_(x)—GeSn, TeSeSn, SbSeBi, BiSeGe and AgInSbTe-typematerials, as disclosed in the '626 Patent.

Once activated, the phase of the light-sensitive material changes to avalid state, thereby permitted convention optical media players to readthe encoded data (block 350). In one embodiment, the activating lightsource may be located at the point of sale of the optical media inquestion. In another embodiment, the optical media itself, or the casein which it is contained, may be labeled in a fashion which indicatesthat the media is unreadable until activated. In this fashion, theoptical media will be rendered useless to a would-be thief until it isactually purchased by an end user.

While the invention has been described in connection with variousembodiments, it will be understood that the invention is capable offurther modifications. This application is intended to cover anyvariations, uses or adaptations of the invention following, in general,the principles of the invention, and including such departures from thepresent disclosure as, within the known and customary practice withinthe art to which the invention pertains.

1. An optical media disk comprising a substrate surface having dataencoded thereon, said substrate surface being treated with alight-sensitive material that is initially in a first phase, whereinsaid light-sensitive material deters theft of said optical media disk bycausing said encoded data to be unreadable while said light-sensitivematerial is in the first phase, and wherein said light-sensitivematerial is to be changed from said first phase to a second phase, priorto a point of sale of said optical media disk, when exposed to a lightsource having a predetermined wavelength, said encoded data to bereadable when said light-sensitive material is in the second phase, andwherein said light-sensitive material is to permanently remain in saidsecond phase after being exposed to said light source.
 2. The opticalmedia disk of claim 1, wherein said light-sensitive material is placedwithin said substrate surface.
 3. The optical media disk of claim 1,wherein said light-sensitive material is inserted in a film that coversat least a portion of said substrate surface.
 4. The optical media diskof claim 1, wherein said light-sensitive material is inserted betweensaid substrate surface and a second substrate.
 5. The optical media diskof claim 1, wherein said optical media is unreadable by a conventionoptical media player while in said first state, and readable by theconvention optical media player while in said second state.
 6. Theoptical media disk of claim 1, further comprising a label affixed to atleast one of said optical media disk and a case enclosing said opticalmedia disk, wherein said label is to indicate that the optical mediadisk is unreadable until activated.
 7. The optical media disk of claim1, wherein said light-sensitive material is exposed to said light sourceuntil the light-sensitive material changes from said first phase to saidsecond phase by absorption of energy from one or more wavelengths oflight.
 8. The optical media disk of claim 7 wherein said first phase isan amorphous state and said second phase is a crystalline state.
 9. Amethod of deterring theft comprising: encoding data on an optical media;treating a substrate surface of said optical media with alight-sensitive material that is initially in a first phase, whereinsaid light-sensitive material deters theft of said optical media bycausing said encoded data to be unreadable while in said first phase;activating, prior to a point of sale of said optical media, saidlight-sensitive material using a light source having a predeterminedwavelength, wherein said activating causes said light-sensitive materialto change from said first phase to a second phase, wherein said encodeddata is readable when said light-sensitive material is in the secondphase, and wherein said light-sensitive material is to permanentlyremain in said second phase after said activating.
 10. The method ofclaim 9, wherein treating comprises placing said light-sensitivematerial within said substrate surface.
 11. The method of claim 9,wherein treating comprises inserting said light-sensitive material in afilm to cover at least a portion of said substrate surface.
 12. Themethod of claim 9, wherein treating comprises inserting saidlight-sensitive material between said substrate surface and a secondsubstrate.
 13. The method of claim 9, wherein said activating occursthrough a translucent or transparent case in which said optical media isencased.
 14. The method of claim 9, wherein said optical media isunreadable by a convention optical media player while in said firststate, and readable by the convention optical media player while in saidsecond state.
 15. The method of claim 9, wherein said light source is amercury-based light source.
 16. The method of claim 9, furthercomprising labeling said optical media to indicate that it is unreadableuntil activated.
 17. The method of claim 9, wherein activating comprisesexposing said substrate surface to said light source until saidlight-sensitive material changes from said first phase to said secondphase by absorption of energy from one or more wavelengths of light. 18.The method of claim 17, wherein said first phase is an amorphous stateand said second phase is a crystalline state.